travis: Add labels to every matrix element.
travis: Add labels to every matrix element.

Just to make it easier to recognize each in the Travis website.

apitrace/apitrace,schulmar/apitrace,apitrace/apitrace,schulmar/apitrace,trtt/apitrace,trtt/apitrace,schulmar/apitrace,trtt/apitrace,trtt/apitrace,apitrace/apitrace,schulmar/apitrace,apitrace/apitrace,schulmar/apitrace,trtt/apitrace